Haist's D-76H Suitability for ANSI Film Speed Test

[Dan Rainer]

I rarely use D-76, but when I do I use the Grant Haist "H" variant. I don't have hydroquinone in my darkroom and The Darkroom Cookbook says that D-76H "works indistinguishably from Kodak D-76."

This has worked fine up until now, but I'm getting into sensitometry and want to perform an ANSI Film Speed test. Do I need to buy hydroquinone or commercial D-76/ID-11? Or is D-76H sufficient for the test?

 

[Milpool]

I’m assuming you mean the ISO speed determination? Under the current standard you can use any developer. The former specified developer formula (pre-1993 revision) was not like D-76 anyway.

Haist’s formula will not be a problem. From a sensitometry perspective it will give very similar results.

I rarely use D-76, but when I do I use the Grant Haist "H" variant. I don't have hydroquinone in my darkroom and The Darkroom Cookbook says that D-76H "works indistinguishably from Kodak D-76."

This has worked fine up until now, but I'm getting into sensitometry and want to perform an ANSI Film Speed test. Do I need to buy hydroquinone or commercial D-76/ID-11? Or is D-76H sufficient for the test?

 

[Dan Rainer]

@Milpool I'm going off of Kodak's Basic Sensitometry Workbook which states "different developers yield different film speeds. The developer specified by ANSI is similar to KODAK Developer D-76." Is this outdated?

 

[Milpool]

Yes unfortunately that part should have been updated. The ISO methodology was updated in 1993 (to replace the 1974 version) mainly to remove the specified developer and fixer formulas and allow these to be at the discretion of the manufacturer as long as the formulas used were disclosed upon request.

For reference, before this change the specified developer formula was:

(/l)
0.5g metol
40.0g sodium sulfite (anh.)
1.0g HQ
1.5g sodium carbonate (anh.)
1.0g sodium bicarbonate
0.2g KBr

Target pH: 9.4 +/- 0.2 @ 20C

@Milpool I'm going off of Kodak's Basic Sensitometry Workbook which states "different developers yield different film speeds. The developer specified by ANSI is similar to KODAK Developer D-76." Is this outdated?

 

[reneboehmer]

I rarely use D-76, but when I do I use the Grant Haist "H" variant. I don't have hydroquinone in my darkroom and The Darkroom Cookbook says that D-76H "works indistinguishably from Kodak D-76."

This has worked fine up until now, but I'm getting into sensitometry and want to perform an ANSI Film Speed test. Do I need to buy hydroquinone or commercial D-76/ID-11? Or is D-76H sufficient for the test?

Metol is a soft-working developing agent that initiates development very quickly, especially in the shadow areas (the toe of the characteristic curve)
Hydroquinone is a high-contrast developing agent that is slow to start but builds density rapidly once it begins, especially in the highlights.
When used together, they don't just add their effects; they multiply them. The hydroquinone "regenerates" the oxidized Metol, allowing it to continue developing. This superadditive action makes the developer more energetic and fundamentally changes the shape of the characteristic curve compared to what either agent would produce alone. D-76H, lacking hydroquinone, is essentially a simple Metol developer (like D-23) and does not benefit from this superadditive effect.

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I would use the developer you like, develop to a ΔD of .80 and define this as box speed. Based on this, the relative film speeds can be calculated.
What you are trying to calculate is your personal Exposure index (EI). You are not trying to measure film speed based on ISO criteria. ISO criteria are used by manufacturers to define speed under exact lab conditions.

 

[Dan Rainer]

Metol is a soft-working developing agent that initiates development very quickly, especially in the shadow areas (the toe of the characteristic curve)
Hydroquinone is a high-contrast developing agent that is slow to start but builds density rapidly once it begins, especially in the highlights.
When used together, they don't just add their effects; they multiply them. The hydroquinone "regenerates" the oxidized Metol, allowing it to continue developing. This superadditive action makes the developer more energetic and fundamentally changes the shape of the characteristic curve compared to what either agent would produce alone. D-76H, lacking hydroquinone, is essentially a simple Metol developer (like D-23) and does not benefit from this superadditive effect.

Good to know regarding D-76H. If I'm trying to get D-76 effects in the future, I might pick up some hydroquinone and mix to the exact recipe.

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I would use the developer you like, develop to a ΔD of .80 and define this as box speed. Based on this, the relative film speeds can be calculated.
What you are trying to calculate is your personal Exposure index (EI). You are not trying to measure film speed based on ISO criteria. ISO criteria are used by manufacturers to define speed under exact lab conditions.

I know this comes up a lot on this site, but I'm not actually looking for a personal EI. I'm trying to use the ISO criteria to work backwards to find the Log H output of an X-Rite 334 sensitometer. (I believe you're in that thread as well.)

Bill Burk and I had a thread on the value of sensitometer calibration a while back. I use "FILM" to calibrate. So in essence I use all my sensitometers like a "Balance," rather than a "Scale." There is always some film used as the comparison. You can also use your "Standard" film's given ISO and work backwards to find the light intensity if you process it via ISO rules.

 

[reneboehmer]

I know this comes up a lot on this site, but I'm not actually looking for a personal EI. I'm trying to use the ISO criteria to work backwards to find the Log H output of an X-Rite 334 sensitometer. (I believe you're in that thread as well.)

Btw this is a feature in my online tool, you can enter a ISO (or close to) conformant curve and it will automatically "calibrate" your sensitometer. But you need to be very precise and using a green light source might introduce issues with this process. Since the ISO lookup table is designed to be used with an ISO compliant white light sensitometer.

All the best!

 

[Dan Rainer]

Btw this is a feature in my online tool, you can enter a ISO (or close to) conformant curve and it will automatically "calibrate" your sensitometer. But you need to be very precise and using a green light source might introduce issues with this process. Since the ISO lookup table is designed to be used with an ISO compliant white light sensitometer.

All the best!

Another feature to appreciate with your tool!
Rereading "The Delta X Criterion" the new ISO Speed Method appears to be independent of developer. Is this correct?

I recognize that my sensitometer might not be entirely up for the task, but it'll be a good learning experience until I can get my hands on a nicer white-light model.